This invention relates to a hydraulic damper for use in particular in a suspension system of vehicle such as an automobile.
Various types of hydraulic dampers have been developed and utilized in vehicle suspension systems.
FIG. 16 shows one typical prior art hydraulic damper which comprises a tubular main body 1, and a piston rod 2 slidingly projecting from the upper end of the main body 1. A small diameter portion 2B is defined on the upper end of the piston rod 2 through a shoulder portion 2A. A tubular sleeve 3 is fitted on the small diameter portion 2B for clamping an upper supporting member 4 of a dish-like configuration between the shoulder portion 2A and the sleeve 3. A bracket 5 is provided for mounting the hydraulic damper on a vehicle body through screws 6. Mounting rubbers 7 and 8 are provided on opposite sides of the bracket 5. A washer 9 is mounted on the upper side of the mounting rubber 8. A nut 10 is screw threadingly mounted on the rod 2 thereby clamping the bracket 5 between the upper side supporting member 4 and the washer 9 through mounting rubbers 7 and 8. A spring 11 extends between the upper supporting member 4 and a lower supporting member 13 to bias the piston rod 2 in the upward direction or extending direction. An annular seat member 12 having a relatively small diameter tubular portion 12A and a radially extending flange portion 12B is secured to the main body 1 by such as welding and the like. The lower supporting member 13 is removably fitted on the tubular portion 12A of the seat member 12 for enabling the replacement or maintenance of the damper main body 1. The lower supporting member 13 includes a small diameter portion 13A removably fitted on the tubular portion 12A and abutting with the radial flange 12B, and a supporting portion 13B extending axially and radially outwardly from the upper end of the small diameter portion 13A and supporting the lower end of the spring 11. Shown at 14 is a mounting eye.
The prior art hydraulic damper having the aforesaid constitution is utilized in a vehicle suspension system by securing the bracket 5 on the body of the vehicle through screws 6 and the mounting eye 14 on such as a wheel axle of the vehicle.
When the hydraulic damper is not mounted on the vehicle, the spring force of the spring 11 tends to extend the piston rod to the most extended position, with the spring force being decreased to nearly zero. Thus, in handling or transporting the hydraulic damper, the lower supporting member 13 fitted on the seat member 12 tends to escape from the seat member 12. For preventing such shortcoming, the lower supporting member 13 has usually been secured to the seat member 12 by screws. However, this arrangement has the shortcoming that the mounting and dismounting operation is troublesome and time consuming.